Using the DITA-OT Server is recommended against the standard Componize DITA-OT Pipelines as soon as there is a requirement for modern DITA-OT server and plugins. Using Componize pipelines remains interesting when speed performance is needed.
The Componize DITA-OT Pipelines were created early in order to solve a problem of performances. Therefore, all ANT integrations are replaced by a proprietary Componize XProc implementation. This implementation remains efficient but is related to DITA-OT 1.8.5 which is an obsolete version of the IDTA-OT.
With a DITA-OT Server it becomes possible to use any version of the DITA-OT, including the most recent one.
With the DITA-OT Server, it also becomes possible to debug locally and then to copy debugged plugins to the DITA server.